Apparatus for pulling a well liner



S. L. WINGER July 26, 1966 APPARATUS FOR PULLING A WELL LINER Original Filed Oct. 7, 1963 Wm W Wm r L A M M L 9M w W f A) Vn/ Y d@ n a f :Whsliwk F J/w 3 Hm @.82 254 2M www0/M E ,4 4 t Q E:

United States Patent() M 3,262,501 APPARATUS FOR PULLING A WELL LINER Sam L. Winger, Taft, Calif., assignor to Midway Fishing Tool Co., Long Beach, Calif., a corporation of California Original application Oct. 7, 1963, Ser. No. 314,275, now Patent No. 3,217,803, dated Nov. 16, 1965. Divided and this application Sept. 23, 1965, Ser. No. 489,642 2 Claims. (Cl. 166-131) This is a divisional application carved out of my cpending application Serial No. 314,275 filed October 7, 1963, now Patent No. 3,217,803, on Method of Pulling a Well Liner.

This invention rela-tes to the art of recovering a well liner from a well and it is a particular object of the invention to provide an -apparatus for pulling a well liner to recover the la-tter after it has been in use long enough for the surrounding formation to have settled against the liner and make the removal thereof fairly difficult.

These liners are perforated to allow the oil to enter from the formation, and are generally several hundred feet or more in length. When completing the well, the liner is suspended by a liner hanger within the lower portion of the well casing and remains there during the production of oil from the well as long as the liner functions properly. The withdrawal of a liner which has been in operation in a well for some time, presents a considerable problem and heretofore has required the use of very expensive special equipment and a highly skilled crew for accomplishing this task.

It is another object of the present invention 'to provide an apparatus for pulling a well liner which will permit this being done by production crews of ordinary skill and without needing any expensive or'specially developed equipment.

The manner of accomplishing the foregoing objects as well as .further objects and advantages will be made manifest in the following description taken in connection with the accompanying drawings in which- FIG. 1 is a diagrammatic vertical sectional view of a well including a well casing and a liner installed in said well, and shows, in elevation, a preferred embodiment of the apparatus of the invention as this is positioned in said well at the beginning of its use (in per-forming the method of the present invention).

FIG. 2 is an enlarged horizontal sectional View taken on the line 2-2 of FIG. 1 and illustrates the rotary valve of the apparatus of the invention.

FIG. 3 is a vertical sectional view taken on the line 3-3 of FIG. 2 and illustrates the packer and the valve of said apparatus with the latter in closed position.

FIG. 4 is an enlarged horizontal section-al viefw Ataken ou the line 4-4 of FIG. 1 and illustrates the manner in which the formation is packed around the liner when the apparatus of the invention is first inserted into the well as shown in FIG. 1.

FIG. 5 is a view similar to FIG. 4 and illustrates the manner in which the formation is expanded by the introduction of liquid under high pressure into said liner (during the performance of the method of this invention) so as to free ithe liner from said formation and permit the same to be withdrawn from the well.

Referring specifically to the drawings, the apparatus or tool of the invention is seen in FIG. 1 as .being installed in an oil well 111 having a main casing I12 in a lower end portion of which a perforated liner 13 has been suspended on a liner hanger 14. The liner 13 is installed in the well 11 Ifor the purpose of producing oil from the oil bearing formation 15 located below the lower end Patented July 26, 1966 ICC of the main casing and surrounding the downwardly extending portion o-f the liner.

As clearly shown in FIGS. l and 4 solid matter 16 from the oil bear-ing formation 15 has settled around the liner 13 while it has been in use so as to be packed against the liner and thus resist efforts made to remove the liner from the Well.

The apparatus 10 is suspendedv at its upper end on a drill string 17 by a pin and box connection 18 between the drill string and the mandrel 19 of a rotary valve 20 which is embodied in said apparatus. The mandrel 19 i-s tubular, having an internal bore 25 of the same diameter as the passage in drill string 17, this mandrel also having an annular flange 26 near its upper end and external threads 2-7 on a lower portion thereof. The portion of mandrel 19 between flange 26 and threads 27 provides a cylindrical surface on which a rotary valve sleeve 28 is mounted. Fixed in a suitable hole provided in annular flange 26 and extending lengthwise therefrom is a limit pin 29, this pin lbeing received in a recess 30 formed in an adjacent end of sleeve 28, the connection between said pin and recs permitting sleeve 28 freedom to rotate on mandrel 19 only between open and closed positions of the valve 20. When said sleeve is in open position, a radial hole 31 provided in mandrel 19 and a radial hole 32 provided in sleeve 28 are in alignment so as to cause the bore 25 to communicate freely with the space outside the tool 10. When the lsleeve 28`is in closed position, holes 31 and 32 are out of alignment and thus communication ybetween bore 25 and the exterior o-f the tool is shut olf by the vvalve 20.

Mounted to extend radially from the sleeve 28 at four equally spaced positions thereabout are four radially expansive pressure devices 33 which are provided Ifor the purpose of engaging the inner face of well casing 12 when the tool 10 is extended downwardly therein to retard rotation of valve sleeve 28 and thus permit valve 20 to be readily controlled by rotation of the drill string 17 from the top of the well. Each of the devices 33 is mounted in a recess 34 formed lengthwise in the periphery of sleeve 2-8 and comprises a pressure bar 35 in which are mounted four coil springs '40 which constantly yieldably expand the bar radi-ally outwardly. Limit fittings 41, held by screws 42 in opposite ends of recesses 34, limit the radial distance outwardly which the springs 40 may expand the bars 35.

The tool 10 also includes a pac-ker mandrel 44 having a box end 45 which is internally threaded to match the threads 27 of the mandrel .19 which is screwed into box end 45 so that the latter serves to hold rotary valve sleeve 28 assembled on the valve mandrel 19. The packer mandrel 44 is turned down to form an annular packer shoulder 46 and a cylindrical surface 47 adjacent'thereto for receiving an annular rubber packer 48. The surface 47 terminates at its lower end in threads 419 for receiving nuts 50 and 51 which hold the packer 48 on surface 47. The packer 48 has a peri-pheral cylindrical surface 55 which slidably tits within the inside diameter of the casing 12, f

and the lower edge of the packer 48 has a pressure seal forming annular fin 56 which is adapted to expand into tight sealing engagement Iwith the casing when liquid under pressure is delivered into the space beneath this packer.

The packer mandrel 44 is provided with an internal' It might be noted however that the spear 60 has three equally spaced circumferentially columns of slips 61 which are retracted out of contact with the liner 13 when the spear 60 is in its retracted condition and are expanded into biting relation with the inner surface of said liner when said spear is in its expanded condition and the spear 60 is shown in the latter condition in FIG. l of the drawings. This view shows the tool after it has been inserted downwardly through the casing 12 on the lower end of the drill string 17 until it has reached the position shown in this view and the drill string then rotated so as to operate the spear 60 to set the slips 61 thereof against the inner surface of the liner 13 and also so as to close the valve which had been left open during the descent of the tool through the casing 12. It is of cou-rse to be understood that the well 11 is prefer- `ably filled with circulating liquid at the start of the operation and the tool 10 is submerged in this liquid throughout said operation.

At the upper end ofthe oil well 11, the drill string 17 is suspended on the usual hook and block or it may be suspended by slips on the derrick floor.

Owing to the close t which the packer 48 makes with Vthe inner surface of the main casing 12, the circulating liquid displaced by the tool 10 and drill string 17 as these descend in the well ows upwardly through the central bore 62 of spear 60, the bores 57 and 25 of mandrels 44 and 19 and out through the holes 31 and 32 of valve 20 into the space between the drill string 17 and casing 12 above the packer 48.

When the tool 10 reaches the level at which it is shown in FIG. 1, the spear 60 is set against the inner surface of the perforated liner 13 and the rotary valve 20 is closed. The circulating pumps are then.started so as to force circulating liquid downwardly through the tool 10 and ont of the lower end of the spear 60 until this causes a sharp -increase in the hydraulic pressure prevailing within the perforated liner 13 and throughout the space extending upwardly from this liner to the lower end of the packer 48 which of course expands into tight sealing relation with the casing 12 responsive to the increase in hydraulic pressure therebelow so as to prevent any of the liquid thus pumped into the liner from escaping upwardly past this packer.

For the purposes of this invention in the experience with it in the field to date, a pressure of 400 lbs. per sq. in. maintained within the perforated liner -13 for a period of from a few minutes to three hours has been found amply sufficient to produce an expansion radially of the solid matter 16 packed around the liner 13 as shown in FIG. 4 until this has separated from the outer surface of the liner as diagrammatically shown in FIG. 5 so as to leave the liner free from frictional engagement with this solid matter for withdrawal from the well by lifting on the drill string 17. A sleeve of liquid 63 thus s formed which lubricates the liner during its withdrawal` .on the packel 48 .itself Which contributes substantially to the lifting force being applied by thevhoist to the drill string 17 for upward withdrawal of the liner. Although expanded tightly against the inner face of the casing 12, the rubber packer 48 is still slidable therein and yields upwardly as the packed solid matter 16 increasingly has its bond broken with the outer surface of the liner 13. By watching his pressure gauge and weight gauge the rig operator is able to observe the increasing ease with which the liner 13 yields to the tension applied to the drill string and thus knows when the liner has been freed sufciently by the sustained hydraulic pressure delivered thereto by the present apparatus, to effect a speeding up of the withdrawal of the liner so as to promptly consummate the latter.

Generally, in the performance of this invention, it is preferable to hold the liquid in the liner under high pres7 sure until the liner has been suiciently freed from solid matter packed thereabout that the liquid pressure may be brought back to normal thus` allowing the packer 48 to retract to its normal diameter and be free from expansive action of the liquid thereagainst during the step of lifting on the drill string 17 for withdrawal of the liner from the well. In this way the packer 48 readily passes over casing joints and other irregularities on the inner surface of the casing which might otherwise impede withdrawal of the liner.

While only a single embodiment of the apparatus of the present invention has been disclosed in the present specification and drawings, it is to be understood that various changes and modifications might be made in this without departing from the spirit of the invention or the Ascope of the appended claims.

The claims are:

1'. In an apparatus for withdrawing a liner from an oil Well, the combination of: a rotary valve having means for securing the same on the lower end of a drill string and operable by rotation of said string between open and closed positions, said valve in open position providing free communication between the interior of said drill string and the exterior thereof and in its closed position shutting olf such communication; an annular rubber packer slidably fitting the inside of the well casing and assembled on .the lower end of said valve; and a spear assembled on the lower end of said packer, there being a central bore extending through said tool and communicating with the bore of said drill string and the lower end 0f said spear, said spear being operable by manipulation of said drill string to optionally set said spear in internal gripping relation With a liner or, after having been so set to disengage said liner.

2. A combination as recited in claim 1 wherein said valve has an internal mandrel provided with a radial hole therein and an external sleeve rotatable on said mandrel and having a similar hole, said sleeve being free to rotate on said mandrel between `two positions in one of which said holes are in alignment and in the other of which they are out of alignment; and yieldable friction means provided on said sleeve which expand outwardly into frictional engagement with the casing of the well when said tool is being inserted in said casing whereby rotation of the drill string on which the tool is carried will permit the valve to be placed in either of said two operative positions by rotation of said drill string.

References Cited by the Examiner UNITED STATES PATENTS 2,190,442 2/ 1940 Costello 166-98 2,430,623 ll/ 1947 Taylor et al. 166-131 2,734,581 2/ 1956 Bonner 166-98 2,965,175 12/1960 Ransom 166-98 CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

1. IN AN APPARATUS FOR WITHDRAWING A LINER FROM AN OIL WELL, THE COMBINATION OF: A ROTARY VALVE HAVING MEANS FOR SECURING THE SAME ON THE LOWER END OF A DRILL STRING AND OPERABLE BY ROTATION OF SAID STRING BETWEEN OPEN AND CLOSED POSITIONS, SAID VALVE IN OPEN POSITION PROVIDING FREE COMMUNICATION BETWEEN THE INTERIOR OF SAID DRILL STRING AND THE EXTERIOR THEREOF AND IN ITS CLOSED POSITION SHUTTING OFF SUCH COMMUNICATION; AN ANNULAR RUBBER PACKER SLIDABLY FITTING THE INSIDE OF THE WELL CASING AND ASSEMBLED ON THE LOWER END OF SAID VALVE; AND A SPEAR ASSEMBLED ON THE LOWER END OF SAID PACKER, THERE BEING A CENTRAL BORE EXTENDING THROUGH SAID TOOL AND COMMUNICATING WITH THE BORE OF SAID DRILL STRING AND THE LOWER END OF SAID SPEAR, SAID SPEAR BEING OPERABLE BY MANIPULATION OF SAID DRILL STRING TO OPTIONALLY SET SAID SPEAR IN INTERNAL GRIPPING RELATION WITH A LINER OR, AFTER HAVING BEEN SO SET TO DISENGAGE SAID LINER. 